66 lines
1.6 KiB
Java
66 lines
1.6 KiB
Java
/**
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* Verweise.java
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*
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* Ein Programm, das die Funktionsweise von Verweisen demonstriert.
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*/
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class Verweise {
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public static void main(String[] args) {
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// Definitionen
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Point p1, p2;
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// Initialisieren
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p1 = null;
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p2 = new Point();
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System.out.println();
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System.out.println("Die Werte der Referenzvariablen sind:");
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System.out.println();
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System.out.println(" p1 = " + p1);
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System.out.println(" p2 = " + p2);
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System.out.println();
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// Das kann zur Zeit nicht gut gehen:
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// System.out.println(" p1 = (" + p1.x + "," + p1.y + ")");
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// Erzeugen von p1 und Verschieben von p2
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p1 = new Point();
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p2.moveTo(2, 3);
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System.out.println();
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System.out.println("Klassen sind Referenz-Datentypen:");
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System.out.println();
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System.out.println(" p1 = " + p1);
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System.out.println(" p2 = " + p2);
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System.out.println();
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System.out.println(" p1 = (" + p1.x + "," + p1.y + ")");
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System.out.println(" p2 = (" + p2.x + "," + p2.y + ")");
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System.out.println();
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System.out.println("Jetzt wird p2 = p1 gesetzt.");
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System.out.println();
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p2 = p1;
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System.out.println(" p1 = " + p1);
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System.out.println(" p2 = " + p2);
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System.out.println();
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System.out.println("Nach dem Verschieben von p1 nach (4,5):");
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p1.moveTo(4, 5);
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System.out.println();
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System.out.println(" p1 = (" + p1.x + "," + p1.y + ")");
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System.out.println(" p2 = (" + p2.x + "," + p2.y + ")");
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System.out.println();
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}
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}
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// Verweise
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